那是某人误读。
the balloon envelope is equipped with either a radar
reflective device(s) or radar reflective material that will
present an echo to surface radar operating in the
200 MHz to 2 700 MHz frequency range, and/or the balloon
is equipped with such other devices as will permit
continuous tracking by the operator beyond the range of
ground-based radar.
这样就行。
【 在 oldwatch 的大作中提到: 】
: 否则为啥航空器规范要求装两套互为备份的主动坠落装置？
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修改:seeasee FROM 122.9.80.*
FROM 122.9.80.*